Investors

News Release

REDWOOD CITY, Calif., March 7, 2016 /PRNewswire/ -- AcelRx Pharmaceuticals, Inc. (Nasdaq: ACRX), a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of moderate-to-severe acute pain, announced today that patient enrollment and dosing in a multicenter, open-label Phase 3 clinical study, known as SAP303, has been initiated. SAP303 is being conducted in patients 40 years and older who have moderate-to-severe acute pain following a surgical procedure. SAP303 will allow patients to be administered one dose of ARX-04 (sufentanil sublingual tablet, 30 mcg) every 60 minutes, as needed for pain management, for up to 12 hours.

"The design for SAP303 is based on the pre-NDA meeting we held in December 2015 with U.S. Food and Drug Administration representatives, and will allow us to increase our experience with ARX-04 in additional dosing practices and patient populations, including those with certain comorbidities," stated Dr. Pamela Palmer, co-founder and chief medical officer of AcelRx Pharmaceuticals. "Given the broad potential use for ARX-04, in various medically supervised settings, such as the emergency department, and for postoperative acute pain management, we look forward to further demonstrating the safety and efficacy of sublingual sufentanil in these patient populations"

SAP303 is expected to enroll up to approximately 100 patients who have undergone a surgical procedure with general anesthesia or spinal anesthesia (except those who received intrathecal opioids). The primary efficacy endpoint is the summed pain intensity difference (SPID) over the 12-hour study period (SPID12). Safety endpoints, such as adverse events and vital signs will also be assessed. The study is expected to be completed by the third quarter of 2016.

About ARX-04

ARX-04 is a non-invasive investigational product candidate consisting of 30 mcg sufentanil tablets delivered sublingually via a disposable, pre-filled, single-dose applicator (SDA). AcelRx is developing ARX-04 for the management of moderate-to-severe acute pain in a variety of medically supervised settings, including the emergency room, outpatient or ambulatory surgery, non-surgical patients experiencing pain in the hospital, and post-operative patients following short-stay surgery, who do not require more long-term patient-controlled analgesia (PCA). ARX-04 is funded in part by the US Army Medical Research and Materiel Command (USAMRMC).

Based on its market research, the Company estimates there are more than 51 million injury-related emergency department visits annually that on average receive 2 doses of opioids for moderate-to-severe acute pain in the United States.

About AcelRx Pharmaceuticals, Inc.

AcelRx Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on the development and commercialization of innovative therapies for the treatment of acute pain. The company's late-stage pipeline includes ARX-04 (sufentanil sublingual tablet, 30 mcg) designed for the treatment of moderate-to-severe acute pain in a medically supervised setting; and Zalviso™ (sufentanil sublingual tablet system) designed for the management of moderate-to-severe acute pain in adult patients in the hospital setting.

ARX-04 delivers 30 mcg sufentanil, a high therapeutic index opioid, sublingually through a disposable, pre-filled, single-dose applicator. AcelRx has reported positive results from the pivotal Phase 3 SAP301 ambulatory surgery study, and has advanced ARX-04 into studies in emergency room patients (SAP302) and post-operative patients 40 years and older (SAP303). Zalviso delivers 15 mcg sufentanil sublingually through a non-invasive delivery route via a pre-programmed, patient-controlled analgesia device. In response to the New Drug Application (NDA) AcelRx submitted to the U.S. Food and Drug Administration (FDA) seeking approval for Zalviso, AcelRx received a Complete Response Letter (CRL) on July 25, 2014. The FDA has requested an additional clinical study (IAP312), which AcelRx is planning to initiate later this month, to support resubmission of the NDA.

This press release contains forward-looking statements, including, but not limited to, statements related to the process and timing of anticipated future development of AcelRx's product candidates, including Zalviso and ARX-04; timing for initiation and completion along with anticipated results of IAP312 for Zalviso; anticipated results and timing of the completion of the SAP302 and SAP303 studies for ARX-04; AcelRx's planned pathway forward towards gaining approval of Zalviso in the United States; and anticipated resubmission of the Zalviso NDA to the FDA, including the scope and timing of resubmission. These forward-looking statements are based on AcelRx's current expectations and inherently involve significant risks and uncertainties. AcelRx's actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of these risks and uncertainties, which include, without limitation, risks related to: any delays or inability to obtain and maintain regulatory approval of its product candidates, including Zalviso and ARX-04; its ability to successfully design, timely enroll and complete the additional clinical study requested by the FDA to support resubmission of the Zalviso NDA; its ability to timely resubmit the Zalviso NDA to the FDA and to receive regulatory approval for Zalviso; the fact that the FDA may dispute or interpret differently positive clinical results obtained to date from the pivotal Phase 3 SAP301 ambulatory surgery study of ARX-04; its ability to complete Phase 3 clinical development of ARX-04; the success, cost and timing of all product development activities and clinical trials, including the SAP302 and SAP303 ARX-04 trials and the IAP312 Zalviso trial; and other risks detailed in the "Risk Factors" and elsewhere in AcelRx's U.S. Securities and Exchange Commission filings and reports, including its Quarterly Report on Form 10-Q filed with the SEC on November 3, 2015. AcelRx undertakes no duty or obligation to update any forward-looking statements contained in this release as a result of new information, future events or changes in its expectations.